"Countless hours of hard work, hectoliters of coffee, tons of improvements, two version numbers skipped, and here it is: the all-new Opera for desktop is now out as an Opera Next version, Opera's channel for what used to be called beta. Made from scratch, this version is available for Windows and Mac and brings a new, elegant design and a bunch of new features that will make your browsing experience sleeker and easier than ever." The first version using something called 'Chromium's engine' - I guess they can't call it WebKit anymore, but they can't call it Blink yet either. It's looking great, but the bookmark functionality seems to not have been implemented yet in this preview

Having more rendering engines make it harder for web developers, but really it is the fault of the rendering engine developers. Thus it keeps everybody on there tows to make sure there implementations work as per certain standards.

Now if Opera didn't have the resources to keep working on their rendering engine and new Opera features, why not simply open source the rendering engine. That would have been much less work than what they did now.